Fewer than 55,000 Americans currently receive treatment in psychiatric hospitals. Meanwhile, almost 10 times that number -- nearly 500,000 -- mentally ill men and women are serving time in U.S. jails and prisons. As sheriffs and prison wardens become the unexpected and often ill-equipped caretakers of this burgeoning population, they raise a troubling new concern: Have America's jails and prisons become its new asylums?

"We are the gatekeepers of a lot of persons who are mentally ill, and that's not something we relish. ... We don't like the idea that we're being charged with fixing a lot of the woes of our communities," says Reginald Wilkinson, director of the Ohio Department of Corrections. "In addition to being the director of the Department of Corrections, I became a de facto director of a major mental health system."

In "The New Asylums," FRONTLINE goes deep inside Ohio's state prison system to explore the complex and growing issue of mentally ill prisoners. With unprecedented access to prison therapy sessions, mental health treatment meetings, crisis wards, and prison disciplinary tribunals, the film provides a poignant and disturbing portrait of the new reality for the mentally ill.

"It was surprising to see how much treatment was going on inside Ohio's prisons," say FRONTLINE producers Miri Navasky and Karen O'Connor. "And while the prison system is doing a commendable job, you are still left with the feeling that prison is not the answer to this very large social problem."

As the rising number of mentally ill inmates shows no sign of abating, those working inside the nation's prisons are struggling with a system designed for security, not treatment. Corrections officers now have the responsibility of not only securing inmates, but also working with mental health staff to identify and manage disturbed prisoners.

"Providing effective psychiatric care in a maximum security prison is extraordinarily difficult," says prison psychiatrist Gary Beven. "If you have untreated manic depression or bipolar disorder, untreated schizophrenia, somebody might be hallucinating and extremely paranoid. If you don't identify the fact that [a] person has schizophrenia, if you don't provide them with the proper medication, if you don't place them in an environment that allows them to function at an adequate level, then it's just a matter of time, perhaps, [that] something aggressive might occur."

And because these inmates have difficulty following prison rules, a disproportionate number are placed in solitary confinement. "People who are just so unsocialized and so psychologically fragile to begin with are deprived of any kind of social support, any kind of psychological stimulus. And they just fall apart," says Fred Cohen, a prison litigation specialist.

Inmate Carl McEachron, sent to prison for stealing a bicycle in 1988, has spent much of his time in prison in isolation, unable to cope with the strict prison environment and racking up an extensive list of violations. His mental illness was left undiagnosed and untreated until recently.

"He was the type of individual who was very difficult to work with," says Beven. "[He's] been very aggressive towards staff, including, I believe, by spitting on staff members and throwing body waste. And so there wasn't a lot of empathy for him. ... The tendency would be for somebody like that to just [say], 'Let's lock him away … let's just not have anything to do with him.'"

"Being placed in a solitary situation is like being placed in a prison's prison," McEachron tells FRONTLINE. "And that's worse than simply being taken from society and placed in prison."

Eventually, a majority of mentally ill inmates are released back into the community, generally with a limited amount of medication, little preparation, and sometimes no family or support structure. "We release people with two weeks' worth of medication. Yet it appears that it's taking three months for people to actually get an appointment in the community to continue their services … and if they don't have the energy and/or the insight to do that, they're going to fall through the cracks and end up back in some kind of criminal activity," warns Debbie Nixon-Hughes, chief of the mental health bureau of the Ohio Department of Corrections.

Within six days of being paroled in 2000, inmate Sigmon Clark, a paranoid schizophrenic, was rearrested for robbery. "Six days with $75 in my pocket. Fare the best way you can, man. We done took 12 years out of your life, and you're mentally ill … do what you can for yourself," Clark tells FRONTLINE.

Some feel change will be difficult to implement.

"Many of those persons who would have been in state hospitals are now in state prisons," Wilkinson says. "I've actually had a judge mention to me before that, 'Hey, we hate to do this, but we know the person will get treated if we send this person to prison.'"